pre calc question

Question

4. Shannon’s cat, Poochie, loves boxes. She wants her finance to make a box for Poochie so that Poochie can jump in the box and sit whenever she wants. To make sure Poochie has enough room, the length of the box be 5 times the width. he is cutting 5 in corners out of the cardboard so he can fold up the sides. he needs to make the box have a volume of 800 cubic in. what are the dimensions of Poochie’s box? round to the nearest inch.

Answer 1

(5w - 10)(w - 10) = 800

 

Can you solve for w and answer?